(a) Field of the Invention
The present invention relates to an improved remote control structure, wherein a memory is disposed on a circuit board within a remote control, and preset encoded data and a normal state of a control terminal are stored in the memory.
When using the remote control, a microprocessor first reads encoded data stored in the memory, and then the encoded data and a control signal is transmitted to the control terminal, whereupon a comparison is made with encoded data stored in a memory of the control terminal, where it is identified whether or not the control signal is a correct control signal, and state data this transmitted back to the remote control.
After the remote control receives the state data signal transmitted back from the control terminal, the microprocessor compares the state data of a controlled body (for instance, a car, a steel roller shutter, and so on) recorded in the control terminal with a previous normal state stored in the memory of the remote control, and identifies whether or not the control terminal is in a normal state. If a normal state is verified, then this latest normal state is written into the memory.
On the other hand, if an abnormal state is identified from the comparison, then the microprocessor reads the last normal state stored in the memory and writes it into a control signal, which is then converted into a wireless signal by a wireless transceiver circuit, and a wireless transceiver transmits it to the control terminal, whereupon the last normal state is written into the memory, thereby eliminating the abnormal state of the controlled body recorded in the control terminal and restoring a normal control state thereto.
(b) Description of the Prior Art
Referring to FIG. 1, when using a conventional remote control A, in order to prevent a wireless signal being transmitted to a control terminal, such as a car anti-theft device, a steel roller shutter, and so on, from being affected by interference from other wireless signals or to prevent decryption of the control signal, encoding switches A2 are disposed on a circuit board A1 or analog switches are used to serve as an encoding device.
However, the aforementioned encoding methods are restricted by the number of switches, which thus limit the number of binary digits (bits) of the encoding. Moreover, the number of encodings correspondingly produced by the analog switches are finite, for instance, a 4-switch DIP (dual in-line package) switch is confined to at most 2 to the power 4 (16) different bit combinations, which restricts both the encoding length and number to 16 bits. Hence, decryption of the encoding can be achieved using current computers that are capable of high-speed computation.
Furthermore, if the control terminal is in an abnormal state, for instance, poor contact in the circuits, abnormal electric circuits, and so on, then the conventional remote control A is unable to correct and restore the control terminal to its original normal state, and there is no other method but to return the control terminal to the factory for repairs.
Hence, the inventor of the present invention proposes to resolve and surmount existent technical difficulties to eliminate the aforementioned shortcomings and provide an improved remote control that embodies digitization, advanced encoding and anti-decrypting capabilities, and further includes ability to memorize and restore the normal state of the control terminal.